MAP20: The Death Domain (The Plutonia Experiment)

MAP20: The Death Domain is the twentieth map of The Plutonia Experiment. It was designed by Dario Casali and uses the music track "Message For The Arch-Vile" from Doom II (the same as Doom II's ).

This level was also ported to PlayStation Final Doom as.

Yellow key
You start in a large outdoor area with one or more arachnotrons, as well as chaingunners on a ledge to your right and revenants in the gray towers on either side; before continuing, you should grab the computer area map to your right then look behind the tower to the north to find a plasma gun. Once done, go to the west side of this area to a dead-end closet with shotgun shells on either side and press the button here, which will lower a set of stairs leading down to a sewer. Head north past some imps to a super shotgun then go east to some barrels before turning left to see another button next to a lift. Press the button to lower the lift then ride it up to the top floor to confront two or three demons who are guarding a blue skull switch. Press the switch then step on the lift again and get off at the middle floor, where a chaingunner is guarding an open door.

You are now in a library. Kill the zombiemen and shotgun guy waiting on either side then head east towards a blank wall, which will lower to reveal an arch-vile (or revenant on I'm Too Young To Die and Hey Not Too Rough skill levels) as well as two Hell knights. Kill them then look in the north-west corner to see a bookcase with a button embedded in it; press this button then head east through a door that opens to reach a room that is seemingly empty except for a partial invisibility. Taking the powerup will cause several chaingunners and shotgun guys to rise from the floor and surround you; the invisibility will offer some protection, but use the plasma gun to kill them quickly. Go through the door in the east wall to confront some spectres then follow the passage up some steps to a marble hall with lost souls, chaingunners and one or more arachnotrons. Head south to the end of the hall, then turn right then left and go round the corner to find the yellow keycard; this item is optional, but may be useful for backtracking later.

Blue key and exit
Walk past the yellow key to a lift and ride it down to an outdoor arena. On either side of the entrance are two alcoves that contain barons of Hell, and once they leave the alcoves they will start teleporting to random points in the arena to blind-side you. Dispatch them then enter the south alcove and flip the switch inside it, which will temporarily lower a wooden barrier between the fences on the north side of the arena. If you run through this barrier you should land inside a fenced pit in the starting area which contains revenants. (If you miss the jump, there is a door in the south-west corner of the starting area that you can open to get back to the arena, but only if you chose to take the yellow key earlier.)

If you land in the pit, walk through it to the blue skull key. You will be teleported to a second pit containing more revenants; push past them to the end of this second pit and you will be teleported to a pad in the north-east corner of the starting room holding a berserk pack. Step off and open the blue key door to the north to confront some chaingunners, then head up the steps to a hall with an evil eye. From here you can walk west to the exit teleporter.

Official

 * 1) Once you reach the lift in the sewer area, rather than riding it up, walk through it to the other side. Go round the corner to find two shotgun guys next to a baron-face wall and press use on this wall, then go back to the staircase leading down to the sewer area to find that a nearby door has opened. Follow a trail of health bonuses to a hidden area with two mancubi, who are guarding a megaarmor as well as boxes of rockets and shotgun shells. (sector 104)
 * 2) In the library area is a wall with two red flags on it. Press use on the light strips either side of this wall to open it, then go through to a lift that leads up to a supercharge. (sector 137)

Non-official

 * On entering the final room with the evil eye, shoot the tan door in the north wall to open it and reveal a megasphere.
 * Also in the final room, go down the south hallway and follow it until you pass a window. As soon as you walk past the window and reach a medikit, run back to the exit room where a ledge with a green firestick in the south-east corner has lowered. Step past the ledge to find a backpack as well as several rockets and clips.

Bugs
Linedefs 179, 194 and 202 (three of four sides of sector 21, at the bottom of the staircase in the starting area) have action "S1 Floor Lower to Lowest Floor" assigned to them; although this step is sunk into the floor, it is still possible to trigger the lines by pressing use on them. Doing so pushes all the stairs down by one stair height, making it impossible to climb back up to the starting area.

Current Compet-n records
The Compet-n records for the map are:

The data was last verified in its entirety on July 6, 2020.

Current DSDA records
The records for the map at the Doom Speed Demo Archive are:

The data was last verified in its entirety on April 16, 2023.

Player spawns
This level contains nine spawn points:
 * 1) facing east. (thing 22)
 * 2) facing east. (thing 25)
 * 3) facing south. (thing 76)
 * 4) facing north. (thing 77)
 * 5) facing south. (thing 83)
 * 6) facing north. (thing 84)
 * 7) facing north. (thing 85)
 * 8) facing south. (thing 86)
 * 9) facing west. (thing 87)

Things
This level contains the following numbers of things per skill level: